We present a first-principles investigation on the dynamics and mechanism of the oxidation reaction between water molecules and the reduced PuO2(110)surface using ab initio molecular dynamics(AIMD)simulations in combi...We present a first-principles investigation on the dynamics and mechanism of the oxidation reaction between water molecules and the reduced PuO2(110)surface using ab initio molecular dynamics(AIMD)simulations in combination with density functional theory(DFT)+U calculations.We find a dominating dissociation preference of water molecules for the vacancy defect sites on the PuO2(110)surface,irrespective of the water or vacancy coverage.Due to hybridizations between the frontier orbitals of water molecule and the electronic states of the vacancy vicinity,partial water dissociation at the vacancy sites is exothermic and barrierless.The dissociation product,an OH group,further hydrogenates the PuO2(110)surface by occupying the vacancy site.We also observe surface vacancy diffusion induced by the interactions between the water molecules and the surface oxygen atom in the proximity of the defect sites.展开更多
基金supported by the Ministry of Science and Technology(Grant No.2016YFA0300902)the National Natural Science Foundation of China(Grant No.21503019)+1 种基金the President Fund of China Academy of Engineering Physics(Grant No.201402034)the Foundations for Development of Science and Technology of China Academy of Engineering Physics(Grant No.2015B0102020)
文摘We present a first-principles investigation on the dynamics and mechanism of the oxidation reaction between water molecules and the reduced PuO2(110)surface using ab initio molecular dynamics(AIMD)simulations in combination with density functional theory(DFT)+U calculations.We find a dominating dissociation preference of water molecules for the vacancy defect sites on the PuO2(110)surface,irrespective of the water or vacancy coverage.Due to hybridizations between the frontier orbitals of water molecule and the electronic states of the vacancy vicinity,partial water dissociation at the vacancy sites is exothermic and barrierless.The dissociation product,an OH group,further hydrogenates the PuO2(110)surface by occupying the vacancy site.We also observe surface vacancy diffusion induced by the interactions between the water molecules and the surface oxygen atom in the proximity of the defect sites.
